Comments

If there is — say some combination of other elements adding to produce a better structure for the ‘cage’ of water molecules that trap methane, say occurring naturally in pore spaces in sediment or leaf litter washed into the ocean — it ought to be discoverabe. Look for it in nature, look for it in theory.

I’ve speculated here before that any such form of hydrate would be commercially _very_ interesting, because it would be stable using lower pressure and higher temperature than currently used for liquefied methane gas.

You mention shipboard and aircraft observations. What of satellite measurements? I was recently pointed to some breathless going-through-the-roof news at the pro-geoengineering arctic-news blog, and from there to a visualization of IASI data at methanetracker.org. Your post puts the implications of these measurements into helpful context. But how reliable are the measurements themselves, compared with other methods?

[Response: I’ve tried and failed to find a good reference to the IASI pictures that are going around. Many of them show obvious problems in the retrieval (i.e. huge jumps at the land/ocean or ocean/ice edge) and I have yet to see what the weighting kernel is or any ground truthing. This is unusual for a remotely-sensed product, and so I’m a little unclear as to what should be concluded. – gavin]

Is methane, and the CO2 it produces, the most likely source of carbon for past hyperthermals? If so, I presume this article means that it could happen again in response to anthropogenic warming but not in the small number of years that some fear – i.e. it would take thousands of years, and we won’t all be cooked to extinction by the end of the decade. Is that correct?

[Response: Methane is the “usual suspect” for those events, such as the Paleocene Eocene thermal maximum, because it is easier to explain the carbon isotopic spikes if the source is strongly isotopically labeled. However, that means we get the answer that there was less carbon released than if it had been, say, organic carbon (-20 o/oo rather than -60 o/oo). For the PETM in particular, the temperature proxies seem to require more warming than a ~1-2000 Gt C methane spike would generate (with the climate forcing agent being the CO2, as documented by its longevity). So I don’t know about methane in the deep past, but I do agree with your conclusion about our future. David]

Re David’s response to #3… I was just about to ask about the isotopic fingerprint. Your comment didn’t quite answer my question, which is whether or not a fingerprint is detectable to source the increasing atmospheric methane? I didn’t see any mention of it in the article above.

How would an ice-free arctic change the picture? A lot more energy is taken up by shallow seas if there is no ice floating on top, warming the sea. Have any model calculations been done to estimate the effects on the methane in the sea bed?

[Response: Yes, and in general the most important consideration is how far down in the sediment column any methane hydrate might be. If it’s hundreds of meters it will take a long time for a change in the overlying water to conduct down to where the hydrate is. David]

As usual, thanks for the perspective. I have to be honest – even with Real Climate’s grounding methane makes me nervous, and reading two nearly simultaneous studies that say we’ve been (relatively) dramatically underestimating the amount of release is unnerving. It seems from a lay perspective this area might deserve closer attention. Maybe we can get Congress to cough up some funding (snark)

I’m also wondering about local, acute effects of the Arctic methane. As stated, because methane is generally “well-mixed in the atmosphere,” then local emissions “must be seen within the context of the global sources,” I assume in order to accurately assess global impact. I’m wondering if the higher local concentrations have a local effect on temperature, and if this might be tied to Arctic temperature anomalies and contribute to local feedbacks. The other thing I’m wondering is if we underestimated the real surface warming since 1998, AND the oceans have warmed more than expected, AND we’ve underestimated at least some of methane release, might methane be a larger forcing factor than previously thought?

[Response: No, I don’t think so. I think the time constant is so long for warming that regional variations in forcing get pretty much smoothed out. I guess the footprint of the regional forcing from sulfate aerosols can be detected in temperature trends, but it’s subtle. David]

Constraints on the Late Holocene Anthropogenic Contribution to the Atmospheric Methane Budget

Anthropogenic and natural sources have different latitudinal characteristics, which are exploited to demonstrate that both anthropogenic and natural sources are needed to explain LPIH changes in methane concentration.

Re: Miller et al’s finding that a bottom-up approach appears to underestimate U.S. methane emissions. Do other countries use similar methodologies and is it likely that methane inventories have been systematically underestimated across countries? I gather that there is speculation that natural gas extraction and distribution is the likely culprit, but my understanding is that Miller et al’s methodology doesn’t allow them to distinguish between potential sources (e.g. leakage at a wellhead vs. ruminant livestock).

“unless these sources suddenly increase by an order of magnitude or more”

This seems to be the crucial question. As you point out, in theory, the methane coming from US fracking and mining is addressable (and should be a priority along with closing coal plant and moving quickly away from petroleum-based transportation systems).

The Arctic seabed methane rate of release, on the other hand, is likely to increase, as you point out. As you also point out, it is hard to know what kind of rate of increase to expect.

Some of the elements driving an increase in sea bottom warming and methane release include:
–increasingly ice free ocean allowing more waves;
–increasing (and increasingly intense?) Arctic storms creating more and bigger waves;
–increasingly ice free seas allowing more time for direct warming of the surface (to how deep?) directly from sunlight and from warmer air temps (although this may lead to greater stratification so could be a negative feedback?);
–increasingly warm waters running into the area from Siberian rivers;
–Atlantic currents becoming increasingly warm and making their way further into the Arctic (more an issue in the Svarlbard area than ESAS?)…

I’m sure I’m missing some others.

So there seem to many reasons to expect temperatures at the bottom of the ESAS and other parts of the Arctic Ocean to warm in the coming years and decades.

How fast that warming could affect the release of seabed methane? It would be nice to have some recent historical background. Do we know how much was coming from this area ten and more years ago? Hasn’t Semiletov said that those amounts were minimal pre-2000? (Sorry, I don’t have a link for this; I’ll see if I can track down the source of this recollection.)

[Response: I’m not aware of this; I’d be very interested if you can dig it up. But also very surprised to hear if methane fluxes were increasing that quickly. The permafrost has been melting for thousands of years. David]

Are there more specific measurements or estimates?

The crucial thing to know, it seems to me, is whether there is a doubling time and what that doubling time has been over the last few years/decades. It doesn’t really matter if relative current values are low relative to total global emissions if they are rising exponentially, especially if they are doubling in fewer than ten or so years.

One more point. I didn’t see any discussion of biological responses to these warming trends. Wouldn’t there be some such, and couldn’t that affect the rates of release (particularly if some kind of seabed worm starts burrowing deeper into the seabed, for example)?

[Response: There is talk of a “compost bomb” feedback in permafrost soils if the climate warms really quickly, and in places where there’s thermal insulation holding the carbon decomposition heat in. Luke and Cox (2011) Soil carbon and climate change: from the Jenkinson
effect to the compost-bomb instability. European Journal of Soil Science, February 2011, 62, 5–12 doi: 10.1111/j.1365-2389.2010.01312.x. But this doesn’t apply under the ocean. David]

An excellent review of methane hydrates. Do we have any data on the relative ages (isotopic methods)of the hydrates in drilled cores? Presumably, this would require some stringent procedures for sample and data collection. Perhaps, some of the compositional variations relate to age.(?)

[Response: Most methane decomposition in the atmosphere is in the tropics, and there is a feedback on its own lifetime, but to get a big shift, you would need emissions orders of magnitude larger than we are discussing here. – gavin]

Sorry, I think my question was too vague. What I’m curious about is whether the buried methane that’s brought up through drilling (I would assume its fingerprint would be different than what is being released in the Arctic?) and then escapes has a detectable signal in the current atmosphere, or is it too small to accurately measure that change with the increase from other sources drowning it out? Also from some of the conversations after my question, sounds like there’s a compositional difference latitudinally, so maybe that actually answers my question?

[Response: Your question was not at all vague, I just don’t remember hearing much about the isotopic composition of methane in the atmosphere. I assume it’s close to -60 o/oo biogenic signature but I haven’t had time to look it up. There seems to be much more analysis of the latitudinal gradient, as you say. David]

We don’t know yet what an ice-free Arctic ocean will mean. What’s the effect of the giant cyclones that filled the Arctic? We have had a few, certainly we should expect more. Will it churn up clathrates? What are the anticipated bio changes to the Arctic waters? With increase summer algae, how much more methane does that mean? When sea level rise causes flooding to areas of permafrost, how much deeper will it thaw? How much more methane is released in deeper thaws? How much will increased Arctic methane affect temps locally? With increased temperatures, what are the increases in rate of permafrost melt? With increased temperature come greater atmospheric moisture, does that mean more rains on Greenland? There have been a few major rains on Greenland, with increased warming, will there be more? Is that modeled? How will albedo changes, increased rainfall and melt in Greenland affect ice degradation?

My point is that there are more ramifications of methane to the Arctic systems.

Thanks for the responses, David. On the Semiletov thing, I seem to have gotten that impression from this piece from CP a ways back: “Since 1994, Igor Semiletov of the Far-Eastern branch of the Russian Academy of Sciences “has led about 10 expeditions in the Laptev Sea but during the 1990s he did not detect any elevated levels of methane.”

I don’t know whether Joe Romm got that from interviewing Igor Semiletov, or if it was something he derived from an article.

I think the point is that, even though, as you say, methane has been leaking from the seabed for millennia, it has not been doing so at levels high enough to make it into the atmosphere at significant levels until quite recently, apparently.

This level of change suggests a rapidly destabilizing situation to many, and hence the concern.

First, I would like to say how much I enjoyed this article and that I imagine that at a 50% confidence level, CL, the author’s positions are well-founded and well-reasoned. Unfortunately, at a 90% to 95% CL matters become much less certain, and risks generally increase non-linearly.

For example, Isaken et al (2011) quantify how as atmospheric methane concentrations increase, the global warming potential, GWP, of methane also increases (see references at end of post). Also note that any source increasing atmospheric methane concentrations, increase the GPW of all previously emitted methane remaining in the atmosphere. As an example of the possible extreme change in radiative forcing in a 50-year time horizon for Isaken et al (2011)’s 4 x CH4 (i.e. quadrupling the current atmospheric methane burden) case of additional emission of 0.80 GtCH4/yr is 2.2 Wm-2, and as the radiative forcing for the current methane emissions of 0.54 GtCH4/yr is 0.48 Wm-2, this give an updated GWP for methane, assuming the occurrence of Isaksen et al’s 4 x CH4 case in 2040, would be: 33 (per Shindell et al 2009, note that AR5 gives a value of 34) times (2.2/[0.8 + 0.48]) divided by (0.54/0.48) = 50.

As NOAA’s Mauna Loa measurement of atmospheric methane concentrations are only currently increasing at a rate of approximately 0.25% per year (or 12.5% change in 50-years); how could anyone be concerned that the change in atmospheric methane burden in 50-years could be 300% (as per Isaken et al (2011) case 4XCH4; which would require an additional 0.80 GtCH4/yr of methane emissions on top of the current rate of methane emissions of 0.54 GtCH4/yr)? At the high CL scenarios, I note the following possible additional sources (beyond or current emissions, and see list of references at the end of this post):

• RCP 8.5 50%CL (which does not consider such possible methane sources as the ESAS, the permafrost or from shale gas) assumes an approximately doubling (Meinshausen et.al. 2011) of the present atmospheric methane burden by 2100, or a 50% increase fifty years primarily due to increase emissions from marshlands and conventional anthropogenic sources.
• Methane emissions from permafrost degradation (see Schuur and Abbott (2011)).
• The Clathrate Gun Hypothesis postulated that methane hydrates can be destabilized due to geotechnical slope failures on the various continental slopes around the Arctic Ocean; which might take decades rather than millennia to accumulate meaningful methane emissions.
• Anthropogenic methane leaks associated with the development of international hydrofracking operations (including significantly that from China) will likely exceed the comparable leaks from USA hydrofracking operations, within one decade.
• The methanetrack.org website has shown significant increases in atmospheric methane concentrations over Antarctica this austral winter (which I believe are due to increases in methane emissions from the Southern Ocean seafloor due to increases in the temperature of bottom water temperatures), and if this trend continues, then the Southern Hemisphere could be a significant source of additional atmospheric methane (this century).
• Similarly, Eillott et al (2011), Reagan (2011) and Reagan and Moridis (2008), for the equivalent of RCP 8.5 50% CL methane emissions from global marine methane hydrates could be 0.3 GtCH4/yr by 2100.
• Significantly, the East Siberian Arctic Shelf, ESAS, has up to 1000 Gt of methane reserves, and it is highly believable that 1% of this (or up to 10 Gt) is in the form of free gas trapped underneath the currently degrading subsea permafrost cap, which could be released within the next few decades by a combination of increasing Arctic Ocean water temperatures, increased storm activity, and possible increases in seismic activity.

From the article: “Methane is a short-lived gas in the atmosphere …The bubbles mostly dissolve in the water column …”

Those two statements lead me to three questions. What are the contributions to atmospheric CO2 likely to be as the methane that makes it to the atmosphere dicomposes? What is the fate of the fate of the dissolved CO2 (how much of that will decompose, and at what rate)? Will dissolved CO2 in Arctic waters ultimately contribute to ocean acidification there? (High latitude are where acidification is most pronounced.)

[Response: Of course it depends on how much methane, how quick. Some scaling: if there were 5000 Gton C as hydrate globally, that’s about the right order of magnitude, if it oxidized in the ocean abruptly, to deplete the oxygen in the ocean. The impact on the total CO2 concentration would be about order 10%. The fate of the dissolved CO2 oxidation product of methane would be for some of it eventually to equilibrate with the atmosphere. The airborne fraction of new carbon added to the system drifts down from 15-25% after equilibration between the atmosphere and the ocean but before neutralization by the CaCO3 cycle and ultimate recovery by the silicate weathering CO2 thermostat. Presumably pretty the same atm/ocn equilibrium would be reached regardless of whether the CO2 started out in the ocean or the atmosphere. David]

That’s the same interview from last August, isn’t it? Has anyone been able to find a transcript and cites/pointers to supporting information?

Has anyone commented that the past claims of “shallow hydrates” would imply the presence about 50x as much methane in the shallow sediments — compared to methane in water or air or sediment not in clathrate form?

Seems to me we heard for a long time the “methane emergency … shallow hydrates” story repeated — and now the “shallow hydrates” term has dropped out of the claims (except for the copypasted repetition of old stories).

But if they’ve agreed nobody has been able to show hydrates above the stability zone, no shallow, metastable hypothetical hydrates found — that should revise the expected methane bomb down to 1/50th — 2 percent — of the claimed size.

How small does it have to get, before it falls within what’s already expected?

Guys, I’m not saying it’s not a problem.

I’m saying it seems an overblown, overhyped, issue that would direct a lot of money and effort into that particular kind of business and government’s projects in that area.

Another paper was published last week, which discusses policy relevance of cutting methane emissions (as well as black carbon and other short-lived climate pollutants): Bowerman et al., “The role of short-lived climate pollutants in meeting temperature goals” Nature Climate Change 3, 1021 (2013). This paper reports an analysis that finds, “[Short-lived climate pollutant] emissions in any given decade only have a significant impact on peak temperature under circumstances in which CO2 emissions are falling. Immediate action on SLCPs might potentially ‘buy time’ for adaptation by reducing near-term warming; however early SLCP reductions, compared with reductions in a future decade, do not buy time to delay reductions in CO2.”

Hank wrote: “past claims of “shallow hydrates”” Who was making these past claims. The stability zones for methane hydrates have been well understood for a long time. So any such claim was either simply confused (something I confess to being on occasion), ill informed, or a kind of short hand for hydrates lying in stability zones beneath shallow waters.

The concern, as I understand it, is that pathways in the latter areas can bring undissolved methane up to the seabed surface, and from there it can make it way through the shallow water column into the ocean surface.

It seems to me that any such pathways, if they are small, would tend to reseal themselves from the cooling effect of the methane bubbles expanding into the ocean water (but this could be another place where I’m confused). But there are presumably other mechanisms counteracting this negative feedback, or we wouldn’t be getting even the amounts reported.

I’m not sure where you are getting your “50x” and “1/50″ figures. Any clarity on this would be appreciated.

“I’m not saying it’s not a problem.” Well, we can certainly agree on that. Let’s all assume that we are all struggling together to figure out the exact nature of the problem.

Thanks for those links, Kevin.

Tenney and hank, I didn’t intend to imply that the interview was from the last few days. But since it is from after the period of the 2011 expedition that the recent Nature paper is about, it is relevant to understanding what they were seeing at that time, it seems to me. If anyone has a more recent interview, please do post it.

OK, yeah, the AMEG folks do occasionally go over the top (or under the bottom?) sometimes. But these days it can be difficult in these matters to know who is an imbecile and who is just a bit ahead of their times.

“The current atmosphere has about 5 Gigatonnes of methane. The East Siberian Arctic shelf has approximately hundreds to thousands of Gigatonnes.

Only one percent of that amount would double the atmosphere burden of methane. Not much effort would be needed to destabilize one percent of this carbon pool, because of

The state of the permafrost
The amount of methane involved
What divides this methane from the atmosphere is a very shallow water column and a weakening permafrost, losing its ability to seal.

It’s a matter of decades, at most a hundred years.

Many factors convince us that a runaway process might happen.

Igor Semitelov is convinced because he spent a lot of time over there, and where the ice should be about two meters thick it was forty centimeters thick. All of the processes that stabilize everything look anomalous, in the sea, the ice, the water column, and the currents under the ice. Because everything looks anomalous he thinks that the worst might happen.”

I recommend a Complex Systems perspective. We can no longer assume equilibrium. Positive feedbacks can push Earth’s climate rapidly to a new regime. Emissions orders of magnitude greater than what we’ve recently recorded are not only possible but probable, given the political/economic determination to monetize fossil fuel reserves over coming decades.

[Response: If this reservoir existed and was so poised to release methane as you speculate, then it would have done something during warmer conditions early in the Holocene, or in the last interglacial. There is no evidence that it did so. Waving hands and saying that we are no longer in equilibrium therefore anything can happen at any moment makes no logical or scientific sense. – gavin]

SkS: In your JGR paper from 2010 you state that methane hydrate in Siberia can occur at depths as shallow as 20 m. Have any such remarkably shallow methane hydrate deposits on the ESAS been directly observed/sampled and if so, how could methane hydrate have formed at such depths?

NS: Yes, such shallow hydrates were sampled in Siberia. They form as a result of the so-called “self-preservation phenomenon” and they are termed “metastable”. This phenomenon has been intensively studied by Russian geologists starting in the late 1980s.

As I’ve pointed out here before, and in other forums, the Russians have been researching the ESAS far longer than anyone else and much of their research has not been translated. Shakhova and Semilitov start from a different vantage point on the research history of the ESAS. Here for instance, you question the existence of shallow hydrates, they take it as already proven and move on.

[Response: Sorry, but that just isn’t very satisfactory. They need to be able to demonstrate that this is a real and widespread phenomena to other people. Curiously, the latest paper doesn’t mention ‘shallow hydrates’ at all, and none were reported in the sediment core they described. There are lots of other researchers on the Arctic continental shelf – including other Russians, USGS etc. No-one else has reported any shallow hydrates, and none of Shakhova’s papers provide any evidence for them either. – gavin]

“…ice formation in pore space when residual water freezing in hydrate-containing sediments stabilizes gas hydrates even when pressure reduction occurs. As a result, gas hydrate can exist in the pore space of frozen sediments for a long time at pressures considerably lower than equilibrium values. So relict hydrates can be encountered all over the cryolithozone.”

Are all of these Russian researchers just wrong?

[Response: That there is a possibility of meta-stable hydrates has indeed been published, but that is not the same as showing that they are actually present to any extent, let alone that there is 50 Gt of them. I have repeatedly asked proponents of this idea to provide actually evidence of their presence on the ESAS as opposed to supposition. It has not (yet?) been forthcoming. – gavin]

As I’ve pointed out here before, and in other forums, the Russians have been researching the ESAS far longer than anyone else and much of their research has not been translated. Shakhova and Semilitov start from a different vantage point on the research history of the ESAS. Here for instance, you question the existence of shallow hydrates, they take it as already proven and move on.

Loads of Russian geologists believe in the abiogenic theory of petroleum formation and have been merrily publishing on this in Russian language journals for decades. Not saying that Shakova’s research isn’t high quality and interesting (or that geologists over there are inherently incompetent), but just because Russian geologists have been publishing stuff in Russian we shouldn’t automatically accept it.

Yep. I followed their cite on “shallow hydrates” and “metastable” — and you should look it up. The reference is not about undersea permafrost, nor about large amounts of material. See the August Unforced Variations thread; repeating the same would be pointless.

You said: “If this reservoir existed and was so poised to release methane as you speculate, then it would have done something during warmer conditions early in the Holocene, or in the last interglacial. There is no evidence that it did so. Waving hands and saying that we are no longer in equilibrium therefore anything can happen at any moment makes no logical or scientific sense.” – gavin

In my opinion, considering far-from-equilibrium possibilities of Climate Change isn’t unscientific. As I see it, a Climate Models without positive feedbacks are as useful as a “scientific model” of a matchstick that doesn’t include the head.

Granted we can’t quantify such complicated interactions. But we can acknowledge their existence and foresee the direction of error that they imply for Climate Models. Almost all of the feedbacks are positive.

Instead of describing our matchstick as just a piece of wood, we can at least say there’s a region whose response we can’t accurately quantify, but we do know that it’s self-feeding and has a huge amount of stored energy. We can admit that we don’t know exactly how much extra heat will set off a reaction out of our control, and that we’re heating it right now. Science is a tool within a larger context. Does logic require one to ignore the limitations of our tools?

Isn’t describing the position of Dr. Shakhova and Dr. Semiletov that runaway warming is at most a hundred years away as “anything can happen at any moment” a straw man argument?

[Response: Sea ice is still not at levels seen during the Early Holocene, and since we are discussing sea floor sediments the main reason given to be concerned is that the change of summer sea ice will warm the bottom sea water, we are clearly not there yet. The rate of warming has nothing to do with the arguments put forward – they are all based on absolute temperature thresholds, so the dismissal of orbitally driven causes is not appropriate. Please note, I am not arguing for Arctic changes to be ignored – they are large, serious and likely to increase – but this does not mean that anything goes. I see no basis for Dr. Shakhova and Dr. Semiletov’s argument that ‘runaway warming is at most a hundred years away’ – the statement is basically meaningless. If they mean a real transition to Venusian conditions, that is ridiculous, but if they only mean to imply that there are some amplifying feedbacks, then there is no argument (except on the terminology) – but the issue is whether they will be large or small. – gavin]

Re “anything can happen at any moment”, Dr. Shakhova did qualify her statement. I left out her qualifications in the interest of brevity. Here’s the relevant portion

56:06
And this is, I think it’s a matter of…
56:10
it’s not a matter of thousands of years, it’s a matter of decades.
56:14
I think, maybe, at most, hundred years but I think,
56:22
matter of decades.
56:25
It might potentially happen because, I would list many factors that might, that are very
56:37
convenient .. convincing for us.
56:40
So that might happen.
56:45
Not anytime.
56:48
Anytime sounds like it might happen today.
56:51
It might happen tomorrow.
56:53
The day after tomorrow.

… this is not the first time this region has experienced warmer temperatures. During some of the warm periods between past ice ages, it has been as warm as, or warmer than, it is today. No sudden spike in atmospheric methane shows up in climate records from those times, however. That tells us that, fortunately, it takes a pretty strong kick to awaken a methane giant.

You should not put the US and Arctic articles in the same sentence. It’s just a way of confusing the Arctic issue.

The US emission miscalculation is meaningless.

The Arctic ‘rate of change’ is devastating. You putting this together with the US miscalculation and saying that ‘Call it 20-30 Tg CH4 per year from both sources.’ is just BAD SCIENCE.

The arctic has just undergone a _doubling_ of methane emissions in 4 years, the reasons are very basic – darker water, less ice, more water saturation of methane, more bubble seems as more methane is exposed to warmth, and of course, more methane in the local atmosphere.

Stop confusing the issue.

[Response: The only person confusing things here is you. There is no evidence whatsoever of a doubling of CH4 in 4 years – the study is talking about a doubling of background level over what was estimated, not an actual increase in flux. – gavin]

[Response: I put them together in part to make the point that the emission fluxes from each paper are about the same. Why isn’t there an American Methane Emergency Group? David]

You can hear a fresh interview on the U.S. methane paper, with lead author Scot Miller from Harvard. He explains what they could and could not attribute to the fossil fuel industry, including tracking propane (which cows do not emit).
Radio Ecoshock interview 20 minutes December 1st.http://www.ecoshock.org/downloads/climate2013/ES_ScotMiller_LoFi.mp3

Gavin #34, “That there is a possibility of meta-stable hydrates has indeed been published…”

Possibility? Their existence has been known for 25 years.

First indications about relic hydrates existence in permafrost of West Siberia (Yamburg gas field area) have been documented at the end of 80-ties – beginning of 90-ties of 20th century. These indications were visible gas liberations from permafrost drill cores from depths less than 150 m when thawing in kerosene or warm water. Drill cores were represented by fine-grained sand and had very small empty space in pores for free gas. Volume of gas liberated when thawing was many times over this space volume.

INTRAPERMAFROST GAS HYDRATES AT THE NORTH OF WEST SIBERIA, Vladimir Yakushev, AAPG HEDBERG CONFERENCE 2004

I can understand disagreements about the total size of meta-stable methane hydrates and/or their potential impact on climate, but what purpose is served by refusing to acknowledge their existence?

[Response: Interesting (link). However, the relevance to shallow hydrates in the ESAS is unclear. -gavin]

Philosophy (Logic and Reason) underpins the scientific method. Without it science wouldn’t be what it is today. So I’d like to take a philosophic view of this discussion on this subject. To begin I note the previous article: “Complex problems often cannot simply be answered with computer models. Experts form their views on a topic from the totality of their expertise – which includes knowledge of observational findings and model results, as well as their understanding of the methodological strengths and weaknesses of the various studies. Such expertise results from years of study of a topic..” […] ” It is important to identify relevant experts using objective criteria.” […] “Most of the experts thus expect a higher rise than the IPCC” http://www.realclimate.org/index.php/archives/2013/11/sea-level-rise-what-the-experts-expect/ The IPCC is noted as presenting ‘conservative’ future projection scenarios. Therefore, “speculation” outside the existing “consensus literature” is acceptable in that topic on RC.

In this article it’s said that ” If anything, the paper is good news for people concerned about global warming, because it gives us something to fix.” imho that’s a nonsequitur and a leading emotive assumption without any evidence to support the statement. Therefore, it is irrelevant in the discussion.

“Methane hydrate seems menacing as a source of gas” another emotive term is ‘menacing’. Seems n/a here.

“…so I personally don’t see hydrates as scarier than frozen organic matter. I think it just seems scarier.” More emotive framing of the topic. Hardly evidence based nor scientific. Again n/a here.

“The scariest parts of the Siberian margin are the shallow parts,…” More of the same. N/A here.

“Significant, but not bombs, more like large firecrackers.” I think the missing word at the end of this passage was “today” – and probably: “Tomorrow we don’t have enough evidence yet to know. Therefore, we don’t know today what could possibly happen in the future.”

@32 Ruth (keeping the SLR article in mind) quotes: “Many factors convince us that a runaway process might happen.” Igor Semitelov is convinced because he spent a lot of time over there, and where the ice should be about two meters thick it was forty centimeters thick. All of the processes that stabilize everything look anomalous..”

To whit Gavin responds: “Waving hands and saying that we are no longer in equilibrium therefore anything can happen at any moment makes no logical or scientific sense.” This is, imho, a complete re-framing the preceding tone and content of prior comments. There was no “waving hands” seen, only text. This is, imho, an emotive re-framing of what was being said. A strawman response, following on form the ‘tone’ of the article’s words by putting emotive hysterics into another’s mouth where it does not fit.

Also Gavin said: “IF this reservoir existed and was so poised to release methane as you speculate, then it would have done something during warmer conditions early in the Holocene, or in the last interglacial. There is no evidence that it did so.”

Well, an absence of evidence is not evidence of absence. Unless of course, there is substantive, well researched studies that show incontrovertible evidence that it was NOT so. Is there?

If not, therefore, no valid logical conclusion can be drawn. The matters rests in the “i do not know” category. Therefore this is not a matter that can be posited either way with any CL, and do so ” makes no logical or scientific sense”. imho.

Therefore, to admit one does not know, due to insubstantial evidence at this time, would be the most rational and logical position to take now, imho. Rather than use emotive terms, instead of being dismissive of others opinions and of others information and suggestions, and to see that it is quite acceptable and reasonable to present conjectures (as opposed to the incorrect semantics of the word ‘speculate’) seems to me to be a more positive, embracing, and open minded approach to take.

Furthermore, again given the theme of the previous article on SLR it appears rational and logical to actually contact Dr Natalia Shakhova and Dr. Igor Semitelov directly (go to the original source) and simply ask them exactly what their professional “opinion and conjecture” is at this time, and why is that so?

This to me would be a far more practical and effective use of one’s time than prejudging their position from the ‘published papers’ (ala the IPCC papers on SLR). It would seem to make more logical or scientific sense not to prejudge their current state of knowledge without doing so first. And then reporting back to those interested on this subject and also thanking them for their input as a simple courtesy before logging a phone call to Russia.

This at least is how Philosophy tends to inform all wise people from all professions since the Ancient Greeks. imho, only of course. I could be wrong, naturally. But that is my best suggestion given the current state of play I see before me.
Apologies for the length to those who struggle. It is not my fault the dialogues have become bogged down and unnecessarily complicated and working at cross purposes here. Unravelling mixed up balls of string takes time. It’s not easy nor simple. Easier to not get so entangled in the first place by following first principles as much as possible. As well as keeping one’s reactive ego and emotions in check.

#43 Sean: I think the scientists here are responding to the large amount of apocalyptic information that appeals directly to emotion out here in the blogosphere. What are they supposed to do, pretend that is not happening? Some anti-emotive reframing is exactly what is required. That is why I keep coming back to this site, it is one of the few places where scientific method seems to be followed.

#42 Gavin,”However, the relevance to shallow hydrates in the ESAS is unclear.”

Unclear? It seems pretty straightforward that if meta-stable hydrates exist in permafrost at shallow depth – then the ESAS is a likely place for them.

The shelf (ESAS)is also characterized by the location of over 80% of the existing submarine permafrost, as well as of the bulk of shallow water gas hydrates.

The Degradation of Submarine Permafrost and the Destruction of Hydrates on the Shelf of East Arctic Seas as a Potential Cause of the “Methane Catastrophe”: Some Results of Integrated Studies in 2011, Sergienko et al, 2012, DOI: 10.1134/S1028334X12080144

What is the history of estimates of arctic marine methane emissions? 20 years ago believed to be negligible. Three years ago, 8 Tg/yr. Today, 17 Tg/yr.

[Response: Still pretty small (3% of global emissions). – gavin]

The fact that the estimates have increased so dramatically is due to research – mainly concerning the ESAS by Shakhova and Semiletov.

[Response: I have nothing against research. – gavin]

We know shallow meta-stable methane hydrates exist outside of the Hydrate Stability Zone in the arctic permafrost.
We know that the vast majority of marine permafrost is in the ESAS.
We know the ESAS is very shallow.
We know that arctic marine methane emissions are far greater than once thought – including (perhaps especially) in the ESAS.

Is the relevance to shallow hydrates in the ESAS really that difficult to see?

[Response: Yes. Because no one has actually reported them there or even provided any convincing evidence for what the sources of methane are. So while I am not saying that it has been conclusively ruled out, the absence of any positive evidence for any meta-stable hydrates in the ESAS, let alone at the levels being speculated about, let alone supposedly being at some heretofore never seen threshold, means that people should not start talking about some huge emission as if it was ‘likely’ or that it could ‘happen any day now’. Neither of those claims follow from the (real) uncertainty and it is irresponsible to claim they do. – gavin]

Just so I am clear on the various positions: Gavin, are you accepting that there was very little methane coming from the ESAS but now there is something like 17 Tg coming from there every year? If so, what would you (or anyone else) attribute this increase to? What do you think the future trajectory of this increase might be and why?

Also, does everyone agree that it is now warmer than it was during the Holocene climate optimum (as has been recently widely reported; see RAG’s link above or ‘oogle relevant phrases)? If so, is the argument that the methane should have come out then relevant? (It seems to me that, even if we have not yet reached that temp for that region, there is no guarantee that the condition of the subsea materials is the same as it was 8000 years ago; in fact, it seems rather unlikely that it is. So again, the argument does not seem particularly germane.)

I think we can all agree that it would be nice to have clear evidence of large quantities of meta-stable hydrates in the ESAS (well, it would be actually nicer to know that this stuff was NOT there, of course).

Didn’t an international team go up to the region in the fall of 2012 to investigate just that? Is it only Shakhova and Semiletov and their teams who have ever done this kind of direct research in these areas?

One more point: Isn’t it possible that salinity levels, in particular, are different now in the ESAS than they were about 8000 years ago in the HCO, not long after most of the ice age ice sheet melted?

Wouldn’t that have an effect on how stable subsea permafrost and clathrates are/were?

Gavin #46- “let alone supposedly being at some heretofore never seen threshold”
The Russians have been writing about this ‘heretofore never seen threshold’ since the 1980’s. The scientific literature has detailed their existence in permafrost outside the HSZ since the 1990’s. And it’s not just the Russians, as Yakushev mentioned in the article I cited earlier, the Canadians have also seen meta-stable hydrates outside the HSZ: see Intrapermafrost gas hydrates from a deep core hole in the Mackenzie Delta, Northwest Territories, Canada, Dallimore and Collett, Geology, June, 1995, v. 23, p. 527-530.

Gas yield calculations suggest that other ice-bearing cores from a corehole in the Niglintgak field also contained non-visible pore space gas hydrate. In at least one instance, the inferred pore space gas hydrate occurred at 119m, a depth shallower than the predicted methane hydrate stability zone. This phenomenon is attributed to self-preservation, a metastable condition where a coating of ice encapsulates the gas hydrate, thus preserving the internal clathrate structure.

“the absence of any positive evidence for any meta-stable hydrates in the ESAS”
These shallow hydrates have been detected in both the Pechora and the Laptev Seas. The Laptev drill site borders the ESAS. Given the geological history, why would these hydrates be unique to the Pechora and Laptev? Shall we just drop ESAS and say Siberian continental shelf? Then your argument that they’ve never been seen disappears.

“or even provided any convincing evidence for what the sources of methane are”
I’m not aware of any real debate. The near surface source is the marine permafrost. And of course there is also methane venting from unfrozen bottom sediments surrounding fault zones and paleo river beds.

[Response: I’m happy to read any references – but even Shakhova in the latest paper or in their 2012 paper do not claim the methane is from shallow meta-stable hydrates. Your absolute confidence that this is the source is not apparently shared by the researchers you’re championing (or perhaps they have not been able to convince the peer reviewers or editors that they can be conclusive on this?). There was none reported in the core they took in the Laptev sea for instance. I have also talked to a number of people – at USGS and elsewhere – that have also looked at sediments in the Siberian shelf and similar environments off Alaska etc. and they have not reported any widespread relict hydrates. Some people have even shown evidence that most of the CH4 is riverine in origin, not from the seabed at all (Bussmann, 2013). But my previous point still stands – there is no evidence that there was a massive methane release in the early Holocene when we know summer sea ice was less and – if you are correct – there should have been even more relict hydrate around. CH4 levels in the ice cores and the gradients between Greenland and Antarctica point clearly to tropical sources dominating the (small) observed Holocene variability. – gavin]

Thanks for that, Kevin. So when you posted “20 years ago believed to be negligible” above, you meant “believed to be, but probably not”??

“*IF* it were the case that arctic methane had doubled and then doubled again in such a short period of time and continued to do so, we’d all be up the proverbial creek without a paddle.”

This is precisely why those of us who (in the words of the recently departed educator, Dr. Bartlett) ‘understand the exponential function’ are so concerned. Again, the operative quote is here:

“Since 1994, Igor Semiletov of the Far-Eastern branch of the Russian Academy of Sciences “has led about 10 expeditions in the Laptev Sea but during the 1990s he did not detect any elevated levels of methane.”

Is there good reason to believe that Semiletov is being misquoted or misunderstood here, or is the area of the Laptev he observed to small to be significant?

Just trying to understand how we might come to the conclusion that these are long term emissions (which I hope we can determine) rather than rapidly increasing ones (which I hope we don’t conclude, but I do want to know one way or the other).

Gavin #50, I love how internet conversations evolve. Do you even remember the genesis of this thread? HR made a comment in #22 “But if they’ve (Shakhova & Semiletov) agreed nobody has been able to show hydrates above the stability zone, no shallow, metastable hypothetical hydrates found — that should revise the expected methane bomb down to 1/50th — 2 percent — of the claimed size.”

I replied in #33 that the literature supports the existence of hydrates outside the P-T calculated HSZ. That most of this has been written by Russian researchers.

You then chimed in refusing to admit their existence. And we go round in circles.

Now you attribute to me: “Your absolute confidence that this is the source is not apparently shared by the researchers you’re championing”

Where have I made this statement or anything close? I’ve merely pointed out that numerous researchers, most of them Russian, have demonstrated the existence of meta-stable hydrates outside the conventional HSZ. That they’ve been found in other similar geologic areas and thus it’s likely they will be found in the ESAS.

When you asked for the methane sources I said permafrost and deep sediment venting. Never have I tried to quantify the occurrence of meta-stable hydrates or inferred that they are the predominant source of arctic ocean methane.

The allusion to peer-review means you’re probably aware most of the papers that have been published included far more examples than actually ended up in the final product. E.g., one early manuscript I found refers to meta-stable hydrates at 20m depth; the final paper was raised to 60m. Another paper had all references to marine meta-stable hydrates removed – even though the original work relied mostly on marine hydrates. Reading between the lines I just assumed they ran into reviewers with attitudes like yours – reviewers that just refused to believe these meta-stable hydrates exist or could exist at such shallow depths.

[Response: I think it far more likely that peer reviewers actually asked that the conclusions of papers actually follow from what was presented and observed rather than imagined. A claim that “X exists somewhere, Y might be associated with X in some circumstances (though Y could arise from many different factors), we have observed Y, therefore X” is just not that convincing. And going from that to stating that it is likely that Y is going to increase by two orders of magnitude any day now is simply unsupportable. I am happy to read more about this, and I have never claimed that there aren’t important methane and carbon feedbacks in the Arctic, but the scenarios that people are discussing (and calculating economic damages from!) are entirely fanciful. People have taken cores in the ESAS (even Shakhova and colleagues) and yet there are no direct observations of these hydrates, let alone 50 GtC of them. – gavin]

and more .. did you note WUWT as the #1 search result then mentally shut down or something? About 5,290,000 results … clearly you didn’t dig very deep nor view to the bottom of the page here. Nor did you do more targeted exact key word searches. Please explain your position, as it is most unclear what the basis for your claim actually is bar a personal “belief”. Thx Sean

The following quote comes from the article (by David):
“Sea level dropped during the last glacial maximum, but there was no ice sheet in Siberia, so the surface was exposed to the really cold atmosphere, and the ground froze to a depth of ~1.5 km. When sea level rose, the permafrost layer came under attack by the relatively warm ocean water. The submerged permafrost has been melting for millennia, but warming of the waters on the continental shelf could accelerate the melting.”
However, as the ESAS was only inundated by the sea about 8,000 years ago it would be highly unlikely to find that about 1.5 km thick subsea permafrost layer would have decomposed sufficiently by the Holocene Optimum to have allow significant amount of methane to leak through it. Nevertheless, by modern times according to Shakhova et al 2010, the area of this ESAS submerged permafrost affected by active fault zones and by open taliks – zones of permafrost that have melted – were 1-2% and 5-10% of the total area respectively. As gases methane would clearly accumulated under an impermeable permafrost cap for the past several thousand years, and as prior to 2010 the ESAS had 5-10% taliks, it is not surprising to say that these observed taliks would have released gases methane from beneath the subsea permafrost in modern times, and that more taliks are likely to continue to be forming. Furthermore, seismic activity has been proven to locally destabilize subsea methane hydrates at many sites around the world. Thus only does not need to postulate a massive destabilization of ESAS methane hydrates, nor to postulate a 50 Gt methane gas reserve, in order to see that continued degradation of the subsea permafrost and continued seismic activity, are sufficient to increase ESAS methane emissions to at least 0.4 Gt/yr (from the current 0.02Gt/yr) within the next few decades; which according to my post #20 may be sufficient to quadruple the current methane burden in the atmosphere by 2060.

To contribute on the issue of satellite observations of methane such as from IASI. Yes, in Europe there is already about 10 years of experience in exploiting space observations of methane in the troposphere. This was pioneered by SCIAMACHY instrument on board of ENVISAT. Our paper in Science in 2005 showed the potential (Frankenberg et al.). These SCIAMACHY observations were backscattered sunlight observations and have good sensitivity to the planetary boundary layer. IASI is the current operational IR sensor on Metop. The methane retrievals are improving over time, and will likely get assimilated in near-real time at ECMWF in the MACC chemical assimilation system to provide in near-real time 3D global fields (and short-term forecasts) of methane. Current inversions rely on GOSAT observations, with eg involvement of JPL. Inversions combining satellite observations and surface data show we know quite the knowns and (regional) unknowns of methane sources. The inversions leave very little space for significant Arctic emissions or emission variations at present day. Please google on SCIAMACHY, GOSAT, IASI, and check the large literature available in eg JGR Atmospheres, ACP, etc. The Netherlands will contribute from 2015 onwards with likely best-ever spaceborne observations of methane with the TROPOMI instrument, part of the European Sentinel series (Sentinel-5p). This mission will allow mapping methane emissions per region and studying the interannual variability of methane emissions from eg tropical wetlands which is hard to monitor from the ground. No mysteries, no doom scenarios, just global-scale monitoring and explaining what you see, that is what we need to do as scientists.

re relict hydrates; Gavin’s comments on this make sense… the issue is not whether such things exist – they likely do — the issue is the 50 GT number. If there was even 0.5 GT I’m thinking we would have much more evidence of such things than we now have. I will also note that even in Yakushevs most advanced studies these hydrates seem very rare…0.5 to 3% saturations? ESAS is possibly telling us something about methane in natural systems, but whether that something is even an uniquely Arctic story or more generic not is unclear. But I think it is pretty clear that is not a hydrate story.

[Response: I would personally bet that metastable hydrates likely do not exist. It would be like an unmelting ice cube thousands of years old. David]

There has been much discussion about previous warm periods, and about why those earlier relatively warm periods did not thaw this sub-sea material. Various arguments against this approach, largely ignored, have been posed.

But, setting aside hydrates for now, I would like to pose a question from a different side of climate pre-history.

It is my understanding that the previous ice ages have ended in the past by a forcing from changes in tilt of the earth (i.e. Milankovitch cycles). But that forcing would not have been sufficient in itself. There had to have been feedbacks that moved the global climate much further in the direction of warming than it would have gone just from the Milankovitch cycles. Am I right in this basic understanding?

Further, the feedback must have included carbon, since the famous graphs show so clearly how closely the initial warming is followed by rises in CO2 (some of which, at least, could have come from CH4). Am I roughly right here, too?

My question is: Since these earlier relatively slight forcings prompted such considerable carbon feedbacks that drove warming much further than it would have gone otherwise, should we not expect some sort of carbon feedback to kick in from our considerable ‘artificial’ forcing/warming?

If so, and if it does not come from the ocean, where are we most likely to see this carbon mostly coming from? Permafrost? Other soils? permanently burned forests? All of the above?

(I still find it a bit bewildering that, if we know well that carbon feedbacks were so crucial to every post glacial warming, this essential element has been left out of most models till recently.)

[Response: Two reasons, no three. 1, The carbon cycle changes in the past were slow, order 1,000 years. 2, We don’t understand how they worked, so it’s impossible to do more than conject about whether and how they will operate in the future. 3. The carbon cycle today is actually acting as a negative feedback, absorbing our fossil fuel CO2. The differences are that we’re forcing it with CO2 rather than temperature (orbital forcing) and the timescale. Models aren’t there yet that can follow this curvey story. David]

“If so, and if it does not come from the ocean….”
As the ocean cools, much more CO2 will dissolve in it and when the ocean warms again the CO2 is released. The carbon comes from the ocean and warming is further enhanced by increasing water vapor.

Thanks, Steve. I had assumed that the CO2 that amplified the M cycles came from a variety of sources: terrestrial, aqueous and seabed… What you say makes sense. Do you happen to have a source where I can look further into it?

#52 Gavin, “People have taken cores in the ESAS (even Shakhova and colleagues) and yet there are no direct observations of these hydrates, let alone 50 GtC of them.”

Gavin, why do you continue to play word games? As I pointed out above, they have been observed in marine sediments in the Laptev Sea bordering the ESAS. They’re part of the same continental shelf. Your position on this is silly.

Furthermore, I believe Yakushev has estimated their coverage to be 0.5% to 3% of the ESAS (sorry, no reference at hand – I could be making this up :)). How many sites would you have to drill before the results would be significant enough to reject the hypothesis? Do you know how many ‘failed’ cores have actually been retrieved? It’s my understanding that it takes specialized equipment to ensure that the hydrate doesn’t immediately destruct when the sediment core is raised; i.e., no one has much data. This should give *more* weight to the fact metastable hydrates were found without even specifically looking for them.

[Response: The ‘no one has much data’ should make you far more sceptical about extraordinary claims than you appear to be. But despite the difficulty, other people have looked, and they have not found. – gavin]

Note, at the observed emission rate of 17 Tg/yr, and using the IPCC GWP of 34 for methane, we’re already at 50 GtC over 90 years. Though the source is, admittedly, up in the air (sic).

[Response: This is a nonsense calculation. A new source of 17 Tg/yr continuously adds approximately 60 ppbv to CH4 concentrations. A radiative forcing of approximately 0.02 W/m2 (directly), or 0.04 W/m2 including various indirect effects. And since this hasn’t been shown to be a new source, impacts are even less. – gavin]

#51 wili – “Is there good reason to believe that Semiletov is being misquoted or misunderstood here, or is the area of the Laptev he observed to small to be significant?”

I don’t believe he’s misquoted, but neither can any extrapolations be made from it. I don’t think anyone knows the answer to: How fast, if at all, are arctic methane emissions growing?. The levels are, at present, too small to have much impact on global levels. But if they’re growing (as a GW feedback) at a substantially high rate, say 7%/yr, then we’d be looking at triple David Archer’s worst case emission scenario to year 2100.

Not only don’t I have a clue as to what the actual rate is, I don’t even have anything to put forward as a reasonable guess. But if the yearly emissions estimate doubles again in the next 5 years we’ll be fast approaching 12 noon in Bartlett’s terminology.

[Response: If you don’t know the rate of growth (which is fine since there is no evidence for anything substantial), I wouldn’t discuss the possibility of emissions doubling ‘again’. – gavin]

At what point will CO2 be released from the oceans? The oceans are warming now but they are still a CO2 sink (hence acidification), even if the rate is slowing.

[Response: Not any time soon. The rate at which CO2 is taken up can of course vary, but I don’t think any projections (at least until 2100) show net outgassing. (Trying to find a relevant reference…). – gavin]

Trapped deep in the ocean floor are huge quantities of methane hydrates frozen in ice structures called clathrates. The total amount of marine methane hydrates could be as much as 100 to 2000 times the amount of methane currently found in the atmosphere. If the ocean floor were to warm sufficiently, causing melting or increased underwater landslides, some of this gas could be released and bubble up to the atmosphere, leading to more global warming. A recent survey of the ocean waters above the East Siberian Arctic Shelf may have located the first signs of such methane release.

Igor Semiletov and his colleagues measured methane bubbling up at a rate 10 times faster than just a decade ago, contributing to spikes of methane in the atmosphere up to 4 times greater than the global average concentration.”

This came out in 2009. So Semiletov was, apparently, doing research in ESAS in 1999 (if not earlier) and the rate seems to be increasing by a factor of ten per decade. So if this rate continued we would have 200 Tg in a decade being emitted from the area per year, and 2000 Tg in two decades?

But perhaps the person writing this story got something wrong?
And is the implication of some of the mods that S&S are basically not to be trusted to present accurate findings?

“Hydro-chemical anomalies obtained over the shallow Siberian shelves demonstrate significant role of coastal erosion in the formation of the biogeochemical regime in the Arctic seas (Semiletov, 1999; Dudarev et al., 2001)”

and for the thoughtful post. Hearing from working scientists here is enormously helpful — both what you’ve done in the past and what you’re working on now, and what you think.

I hope you’ll keep giving us pointers to real information as you did above.

Please google on SCIAMACHY, GOSAT, IASI, and check the large literature available in eg JGR Atmospheres, ACP, etc. The Netherlands will contribute from 2015 onwards with likely best-ever spaceborne observations of methane with the TROPOMI instrument, part of the European Sentinel series (Sentinel-5p). This mission will allow mapping methane emissions per region and studying the interannual variability of methane emissions from eg tropical wetlands which is hard to monitor from the ground. No mysteries, no doom scenarios, just global-scale monitoring and explaining what you see, that is what we need to do as scientists.

Wili, the NWF link you posted above repeats the same claim that appears many other places, it’s not news, and it’s not new. That says, without a cite:

A recent survey of the ocean waters above the East Siberian Arctic Shelf may have located the first signs of such methane release. Igor Semiletov and his colleagues measured methane bubbling up at a rate 10 times faster than just a decade ago …

It’s the same story posted, reposted, and reposted over and over and over.

Seriously, no matter how many times a claim is copypasted to a new Google link, no matter how big the Google hit count goes up — it’s the same item.

It’s been claimed once, unsupported — and reposted thousands of times, as whatsisname illustrated a while back with the same notion.

Multiple copies generate more links and search hits that benefit the SEO “optimizers” — hit rates pay them money. People load their pages with multiple copies to get more clicks — but that’s nothing new.

Thanks for your response to my inquiries at #57, David. There you write: ” 2, We don’t understand how [earlier carbon feedbacks] worked, so it’s impossible to do more than conject about whether and how they will operate in the future.”

I find little here to take comfort in (not that it’s your job to comfort us).

Given that every other time there was a temperature forcing, the system eventually responded with a re-enforcing carbon feedback, it would seem pretty likely that the same will happen eventually this time.

[Response: I feel it’s as if we sit under a sword of Damocles, within a very viscous fluid in which it will take a long time for the sword to reach us if (when) the string breaks. David]

I guess the whole debate here boils down to the definition of ‘eventually': How soon and how abruptly might we switch from net negative carbon feedback to net positive?

I join hank in thanking not only Michiel van Weele but all those struggling, often heroically, to research these important developments and to make that information broadly available.

… working to institute a system to ensure that the scientific community and the public can more easily distinguish between WWF’s peer-reviewed scientific reports and our general communications products….

disambiguation, to be clear: both the NWF and the WWF produce both peer-reviewed science and more general blogs and columns. I mention the WWF as an example of the problem any such group may have when their general blogs and columns make claims without cites — don’t assume everthing you read is good science. Their hearts are in the right place, but their cites may or may not be.

Ha! Thanks for the WWF link, hank. My bro used to be their main man in China so I used to stay on top of what they were doing more (before he went on to run IATP; the over-achiever in the family–my job is to hold down the other end of that spectrum ‘-)).

If you go to the National Wildlife Federation page you cite and go to the pdf they link to, the NWF is citing a 2008 National Geographic news story about Semiletov’s AGU presentation. National Geographic interviews Semiletov for the article and the “spikes of methane in the atmosphere up to 4 times greater than the global average concentration” comes directly from a quote from Semiletov.

The NWF in the following paragraph states that the chances of mass marine methane hydrates releases are remote, but if this does happen the result’s can be very serious (and cite a paper published in Nature) so it cannot be ignored.

It is important to remember that the environmental groups are political advocacy groups. How accurate are their claims depends on how they use the science. This varies from group to group, but the major U.S. groups are sophisticated and have working scientists on their staffs. Although they tend to play up the worst case scenarios, they usually don’t make baseless claims.

Over at the environmentalist news site Grist, I have been arguing that environmentalists should be careful about making claims that cannot be based on scientific facts. Recently the stories about the papers that are the subject of David’s post have come up, and I think the Grist author’s are making claims that the studies really can’t support.

—-
On a lighter note, here is a beautiful and somewhat creepy video of a ‘brine-icle’ transporting very cold brine down from below the sea ice to the ocean floor and freezing everything in its path. Just shows that there are all sorts of weird, unexpected ways that temperature, salinity … can be communicated from one level to the other in the ever-surprising Arctic.

So, we have quotes from a scientist doing field work along the Siberian coast, showing that methane emissions from the ESAS were negligible, more than 10 years ago but are now far, far greater. We have other scientists who appear to show disbelief in such statements.

Who should a layperson give more weight to? Why do we have such apparent disparate views? Whether it is shallow hydrates or free methane (perhaps from hyudrates) previously under an impermeable permafrost cap, something does appear to be happening up there. Some scientists think there is nothing much to worry about yet and others think there is. And there seems to be some animosity between those who consider themselves experts on this (not just S&S) and others who consider themselves experts on this. But who are the experts and, to repeat, who should a layperson give more weight to?

I’m trying to understand what is going on the in Arctic but it seems to be an impossible task, though some people (on both sides) seem perfectly convinced of their alternate views.

Tony (#77),
The way out of your conundrum may simply be not to get carried away with qualitative rhetoric (“far, far greater” or “worry”) and leaps of logic and to focus on the specific claims beign made.
As far as I can see, there’s only one “side” who has spoken competently in quantitative terms about the global impact of this stuff.
If there are bubbles of methane here and there boosting the local CH4 concentration spectacularly but which on the global level amount to less than 3% of the effect of CO2 emissions from fossil fuels, what does it matter really?

A layman may also watch the CH4 readings from the monitoring stations whose data is released to the public in a timely manner.
If there are new sources of methanes which aren’t “negligible”, where is the stuff hiding?

Tony, I’ve tried to imagine the conditions in which the Russian warnings could be serious; near as I can tell they’d need something different now, some new mechanism for carrying heat down into the stability zone. Something that did not happen in the paleo record.

For example, is the seabed there riddled with unplugged boreholes from oil and gas exploration? Enough to allow warm water to circulate down deep through gravel beds into the “stability zone” where hydrates are found.

Or are there now somehow far more faults in the permafrost than existed in paleo times?

That mechanism would be analogous to how an aquarium undergravel filter works — bubbles rising up one opening draw water down through other openings.

That would warm material faster than it can warm by heat diffusing through intact sediment.

But that’s pure speculation. That’s an attempt to guess what could possibly be behind the claims being made that it’s a problem now that didn’t happen the last time the area was as warm or warmer than now.

What could be worse? Dump old nuclear reactors onto the seabed near open boreholes, say, or on top of open faults that would lead warm water down to the stability zone? Could have happened.

Are there sensors in the area we aren’t told about? You’d expect so, since several nuclear navies have been active in the Arctic for decades. But we don’t know.

AC at 78 wrote: “If there are bubbles of methane here and there boosting the local CH4 concentration spectacularly but which on the global level amount to less than 3% of the effect of CO2 emissions from fossil fuels, what does it matter really?” It matters if the levels are increasing at an exponential rate. That seems to be the main question before us.

Hank: As usual, many good points. On the last bit, would point out that one scientist that I know has been working closely with the Royal Navy in the Arctic since the ’70s is Peter Wadhams, and he is far from sanguine about the rapidly changing conditions there and their likely consequences. (It is rather a pity that he threw his authority behind the AMEG folks, many of whom do…sloppy work sometimes and most of who have become rather rigidly ideological, in my view. But the very fact that he was drawn in that direction speak–to me–to the likely extremes situation he sees the situation being in from his advantaged, long-term perspective on the area.)

“He has pioneered the use of AUVs (autonomous underwater vehicles) to measure under-ice topography and has worked with the Royal Navy since the 1970s in carrying out ice thickness measurement work from Navy submarines on Arctic deployments.”http://www.4cmr.group.cam.ac.uk/directory/pwadhams

I have not taken the time yet to find out what other major researchers have worked with various navies in the area. Do you know of any?

@81 re http://iopscience.iop.org/1748-9326/7/1/015201/pdf/1748-9326_7_1_015201.pdf Received 5 August 2011 – Accepted for publication 6 December 2011 Published 4 January 2012
Page 11 Summary Statements
“To answer these questions we call for extended
international cooperation in studying the ESAS. Such study
will require multiple year-round exploration campaigns,
including drilling of sub-sea permafrost to evaluate the
sediment CH4 potential and comprehensive atmospheric
measurements to assess the ESAS strength as a greenhouse gas source.
“International effort should also be joined in order to quantitatively assess future changes in greenhouse gas emissions in response to ongoing climate change by establishing and developing regional numerical models with the aim of incorporating them into global climate models.”

I have no idea as the the scientific validity nor qualitative rigour of the work done by the Russians. What I do know is that the pattern of human psychology is constant across the boundaries of individuals whose beliefs are either pro or con a particular hypothesis based on existing hard evidence. The beliefs and opinions vary, whilst the psychology of forming them and defending them are not. The modus operandi is in fact exactly the same.

Denial is not a river in Egypt. Dismissiveness is dismissiveness always backed up by rhetoric and sophistry and usually not by hard evidence. An absence of evidence is NOT evidence of absence. Until such times as the appropriate basic research has been done and analysed properly. Rhetoric is not science, it is only ever about talking and listening.

The Russians have repeatedly asked for help from the rest of the global scientific community on the subject of the ESAS. This doc is but one example of that.

28 months later, since they wrote this quoted Paper/article, some elite and well resourced scientists cannot even bring themselves to send the authors an email or make a phone call to inquire what the authors evidence and opinions as of Dec 2013, or if there is some new papers coming out soon on this subject.

Yet they do have all the time in the world to waste arguing about the absence of evidence on a discussion board with the general public and defending their beliefs not based on evidence. This reminds me of WUWT and Curry’s & Jo Nova’s blogs and the US Congress debates over Climate Science. Incredible maybe, but it seems to be true. Aaah but would I know about such matters? Carry on.

Unfortunately, I think you are likely right, hank. Thanks (yet again) for that link. I had not known that Gore tried to do (or if I did once, I have long since forgotten it—happening more and more these days :-/ ).

Yes, I read the comment you linked to but am no clearer about the likely situation up there. Wili points to Wadhams, Shakhova and Semiletov who would all regard the situation as somewhat worse than Archer and Schmidt do here, with the definite potential for abrupt releases. Wili has also pointed to information suggesting that we did have data (collected by Semiletov) in the 90s which showed no elevated methane emissions in the ESAS but now we have 17 TgC per year, estimated. Is that not a worry to Archer and others? If not, why not?

Anonymous Coward,

The worry is not so much that there is already an abprupt release (though methane concentrations are on the rise) but that there are pathways for such abrupt release. The problem may not be metastable hydrates but free methane beneath subsea permafrost.

I would just like to point out one perhaps telling juxtaposition in the last line from the generally excellent and helpful post made by van Weedle at #55: “…no doom scenarios, just global-scale monitoring…”

Contrasting these two this way makes it sound as if scientific collection of facts from “global-scale monitoring” can somehow never lead to “doom scenarios” and that, if they do, the monitoring or its interpretation must be suspect; not really a valid assumption afaics. But perhaps I’m misinterpreting the assumption behind this contrast somehow?

(In any case of course, plenty of facts and interpretations from climate-related global monitoring of various sorts are indeed already pointing in very doomy directions, more and more so every week, it seems. At this point, a certain amount of “doom” is pretty much baked in. The operative question is how fast and how much. And, of course, at least some of what will determine those “how’s” will always remain partly in our individual and collective hands, depending on how soon we choose to stop making the problems worse, i.e., how soon we choose to stop burning ffs, and stop breeding and eating methane-producing animals…)

(reCaptcha oracle implores: “act rkholid” …now if I only knew what ‘rkholid’ meant, I would know how to start to act ‘-))

Has anyone else read the recent report from the National Research Council of the National Academies? It discusses this issue and concludes that sudden release of methane from ESAS is unlikely this century, but that the area needs to be studied more. It’s long, but well worth a perusal, at least, imho.

(I hope my bringing up this important work helps people to see that I don’t see this as some kind of high school debating club, but as a forum to bring forward as much relevant research as possible to increase general understanding of the issues.)

Of course, this report does not represent new research, afaics, just an assessment of older work. And, of course, such collective efforts tend to be conservative. I hope we can all agree with their conclusion that more research is needed in this (and in a number of other) crucial area(s).

I just go to the section where they get into discussing Arctic seabed methane in more detail, and the conclusion of that section is actually: “In summary, the ocean methane hydrate pool has strong potential to amplify the human CO2 release from fossil fuel combustion over time scales of decades to centuries.”

Thanks for your response at #70, David. “I feel it’s as if we sit under a sword of Damocles, within a very viscous fluid in which it will take a long time for the sword to reach us if (when) the string breaks.”

Striking analogy! I guess what is up for debate is not so much whether there is a sword, but how big it is, how thin and frayed the string is (when/if it will break), and how viscous the fluid is. (I must admit that my old eyes first read ‘vicious'; perhaps equally fitting.)

Anyway, thanks again for the response, and for all your important work.

[kto]”Not only don’t I have a clue as to what the actual rate is, I don’t even have anything to put forward as a reasonable guess. But if the yearly emissions estimate doubles again in the next 5 years we’ll be fast approaching 12 noon in Bartlett’s terminology.”

[Response: If you don’t know the rate of growth (which is fine since there is no evidence for anything substantial), I wouldn’t discuss the possibility of emissions doubling ‘again’. – gavin]

Once again you respond to something I didn’t write. I didn’t say emissions doubling again, I said emissions *estimates.* I expect words to be twisted on denier sites. Not here. Or are you now going to claim that the emissions estimates haven’t doubled in just a few short years?

[Response: Fair point, apologies. However the estimates of natural CH4 sources are all quite uncertain – with the main constraint being on the total emissions, not individual sources. Thus any reexamination of any particular source usually just rejiggles the ordering of terms, but doesn’t really change the overall picture. Even if ESAS estimates doubled again, it is still a small number. – gavin ]

Here is what I don’t understand about this Arctic business. This shelf has been hit with a gigantic thermal pulse of 13C as relatively warm water replaced cold air. So why do we think that an extra degree or two of air temperature change above that water is going to be some key tipping point?

You implied that there was nothing in the paleo record showing a rapid release of methane but there was a paper in October suggesting a very rapid release which caused warming of 5C in 13 years (and rendered the ocean surface acidic). There is a report of the paper at Climate Progress.

I couldn’t find the paper mentioned at RealClimate and wondered why that paper appears to have been overlooked?

[Response: Wow, that’s a great paper. A game-changer. They have evidence that the carbon was released as you say very quickly, essentially instantaneously. I’m not a field geologist, but this looks to me like the kind of geologic section one would click one’s heels together to make a wish for, like I heard Steve Gould describing the Burgess Shale. Fantastic! Zachos measured individual foram shells from the deep sea, and found that for the planktonic ones, they were either heavy or light, never transitional. For benthic ones, there were transitional ones. Seemed to me that was also evidence for an abrupt carbon release, but Jim pointed out that dissolution might have created the signal he saw. This changes the playing field considerably for proposed sources.

They also weigh in on the magnitude of the 13-C change and the amount of C released. They extrapolate the 13-C spike in the ocean against depth to estimate an atmospheric 13-C change, just after the carbon has been added to the atmosphere and before it invaded the ocean much at all, to get 20 o/oo. Then the magnitude of the carbon spike depends on its isotopic composition. This is a slightly different constraint than the previous calculation everyone’s done of the 13-C change in the deep ocean, representing the signal after it’s all mixed in (at least a few thousand years later). The results of the two seem to be similar on one end of the spectrum, in that biogenic methane (-60 o/oo) requires about 1000 Gt C. But the amount of carbon required to achieve an atmosphere of -20 o/oo with organic matter is prohibitively large. So they end up picking thermogenic methane of -40 o/oo as a feedstock. I guess I’m dubious on this conclusion; the extrapolation to an atmospheric 13-C seems like a sketchy way to eliminate the possibility of a larger, less isotopically labeled organic carbon source.

Because there is still the constraint that the carbon has to lead to the warming. They state that addition of 3000 Gt C to an atmosphere of 2000 Gt C would lead to warming of 5 degrees C, but I don’t believe it unless the climate sensitivity is much higher than today. This is the issue raised by Pagani et al (Science 2006 10.1126/science.1136110). The warming has to be due to CO2, as evidenced by its duration. The atmospheric fraction of that instantaneously released CO2 would drop quickly as it invaded the oceans, while the thermal response of the Earth will be slowed by the thermal inertial of the oceans. So on the time scale for temperature equilibration of the Earth, you’d probably have less than a doubling of atmospheric CO2, not enough to get 5 degrees C if the climate sensitivity is as today about 3 degrees C.

Truly a cautionary tale, and the geologic record is full of them. But I maintain that the best way to assess whether a methane blowout is likely in the near future is the world as it is at present. We are still at the stage of speculating on the causes of the PETM. David]

Sekerob, iirc, the “Bermuda Triangle” is completely mythical. Careful statistical analysis of the frequency of losses at sea show no increases of such accidents in that area over any others in the Atlantic. Of course, that does not negate the possibility of the specific kind of event you seem to be claiming has happened with sudden methane release.

(that’s why Gavin asks us to always provide the DOI — it’s the only reference that’s always going to be reliable to find a science paper; bit rot and ambiguity breaks connections and searches otherwise)

We poked at a few questions given what we knew at the time of publication.

Has more been published (or talked about in the hallways at meetings) on this one yet? I’d imagine people at this week’s AGU annual meeting will have, as Peter Watts puts it, kicked the paper around to see how it holds up.

I recall some people on Gavin’s Twitter feed arguing against this notion of a hyper-rapid methane release.. problem with interpretation of annual layering in that study. Perhaps after AGU, there would be some friendly guest debate on this at RC?

Prof. Archer, thanks for the comment. I agree with you assessment of Wright (2013), that it is a paper that, if verified, is groundbreaking revision of the speed of PETM onset. I had previously commented:

“Fig. 4 shows the effect of ocean depth of sediment deposition upon the size of the delta-C13 excursion.

1)This is very nice becoz it shows a path to reconcile deep and shallow sediment records from PETM.

2)This is also nice becoz it uses the Archer model

3)Coupled with the time differentiated CaCO3 and delta-C13 response, it is a nice test of the Archer model.

4)Wouldn’t it be nice if Archer would comment ?”

Couped with your comment on the Zachos findings, would you care to add your thoughts on the time differentiated response of CaCO3 and delta-C13 response as a test of your model ?

sidd

[Response: I don’t have a model of the scenario they’re talking about. They want an instantaneous increase in atmospheric CO2 I suppose, which leads to an instantaneous decrease in pH and hence CaCO3 burial and a somewhat slower change in the carbon isotopes. New invading CO2 will carry the new atmospheric isotopic composition but the water still has more isotopes to exchange to reach equilibrium, and so it will take much longer before the isotopes respond fully. That sounds good to me. But I don’t think I’d bet the farm on the global reliability of that CaCO3 record. It wasn’t very much to start with (4%), and %CaCO3 measurements tend to wiggle. However, that leaves the decadal time scale of the 13C isotopic composition change, which seems consistent to an instantaneous spike of CO2. David]

Thanks for the tips on searching. I couldn’t find that reference previously but I see it was there. I now recall seeing that but, not being able to understand the abstract, didn’t pick it up until I saw the ClimateProgress article. (BTW, I’ve never got the site search box to produce any results, so I don’t bother with it any more – probably just my setup)

I notice David didn’t comment on it earlier and I guess his long response suggests that he wasn’t aware of the paper prior to my link. It’s good that he’s now considering it as a game changer.

Just to comment on his response. I had noted from James Hansen’s writings talk of climate sensitivity depending on the current climate (I remember seeing a graph of this but can’t find it right now). Also, the current climate sensitivity estimate has error bars, so that the current climate sensitivity may be as high as 4.5 degrees C, so 5 degrees at the PETM may not seem so out of kilter. But what would 3000GtC release mean in our current climate? With the Arctic permafrost and clathrates now fully charged, is it hypothetically possible that such a rapid release could happen in our current situation?

#94 “Even if ESAS estimates doubled again, it is still a small number.” – gavin

The methane emissions for the entire world ocean were estimated at less than 4Tg/yr just 15 years ago. Then the arctic contribution alone was increased to 8 Tg/yr and then 17 Tg/yr. Now, I can easily understand that no one was systematically looking at methane in the arctic and the uncertainties were known to be large, so the fact these estimates have grown could easily be due to better estimates not increased emissions.

At some point though, if the estimates keep increasing there is a good chance it’s due to emissions actually increasing. It really doesn’t matter what the number is today, if it’s doubling every 4 or 5 years then it’s a looming disaster.

We agree that no one knows the rate of growth. I think we agree that global warming will increase that rate (whatever it is today). Your position seems to be: we don’t know the rate, we don’t know how much it is going to increase, there are large uncertainties in the current estimates – but don’t worry. I’m not comfortable until we know the rate and and verify that it is small. I don’t find a lack of knowledge and large uncertainties as a reason to be complacent. Especially in the arctic where everything that has transpired the past 20 years seems at a pace that far exceeds our expectations.

Wow, that’s a great paper. A game-changer. They have evidence that the carbon was released as you say very quickly, essentially instantaneously

Live reports on Twitter from AGU mention a talk by Richard Zeebe that was sharply critical of this research (although also a presentation from Schaller continuing to promote the idea). For example see Jessica Tierney:

Love David’s inline @ #97 in response to Tony Weddle! It’s great when the conversation brings information to the moderators (who may be in a position to do something useful with it, scientifically speaking.) Kinda validates all the yakking, in a way.

Some thoughts, mostly in the form of questions:

>”…Seemed to me that was also evidence for an abrupt carbon release, but Jim pointed out that dissolution might have created the signal he saw.”

Because the planktonic transitional forms didn’t survive in the acidic waters? Also, “Jim” must be James Wright, senior author on the paper, but who is “Zachos?”

>”The warming has to be due to CO2, as evidenced by its duration. The atmospheric fraction of that instantaneously released CO2 would drop quickly as it invaded the oceans, while the thermal response of the Earth will be slowed by the thermal inertial of the oceans. So on the time scale for temperature equilibration of the Earth, you’d probably have less than a doubling of atmospheric CO2, not enough to get 5 degrees C if the climate sensitivity is as today about 3 degrees C.”

I don’t get this. (Maybe if I’d actually done Dr. Archer’s online course!?…) But if the temperature transition took only 13 years, wouldn’t you expect a methane/CO2 mix? And a strong feedback due to massive dieback of terrestrial vegetation and marine plankton? If so, might not the CO2 levels fail to drop quite so quickly after all?

[Response: Could be… you’re asking for methane to boost the initial warming faster than the deep ocean would like, and then have more carbon come out later to account for the 5 degrees C temperatures a few thousand years out. But it’s the long-term temperature that provides this constraint, and if we’re both saying that it takes more carbon than you would get from methane to drive the long-term warming, than we agree. Remember that any biosphere carbon would bring its own isotopic signature. ]

Perhaps David considered all these (probably naive) points. But even so, I’m left wondering “What *would* be sufficient to spike temps 5 C in 13 years. Still more carbon, presumably?” Which leads onto:

[Response: I don’t know what it would take; this is way faster than climate models are usually pushed. ]

>”They also weigh in on the magnitude of the 13-C change and the amount of C released. They extrapolate the 13-C spike in the ocean against depth to estimate an atmospheric 13-C change, just after the carbon has been added to the atmosphere and before it invaded the ocean much at all, to get 20 o/oo.”

I think that defining terms here would help some of us–yes, that’s “me”–out. I initially thought “13-C” referred to temperature. Now I’m wondering if it’s the carbon isotope? And how about 0/00–“parts per thousand?” (As referenced here.)

[Response: Yes, so sorry for causing you work by being unclear. Yes, I meant delta-13 C, which is usually written with a genuine lowercase greek letter delta, and expressed as per-mille which is parts per thousand (analogous to percent is parts per hundred). ]

If those interpretations are correct, then I’m thinking the burden of this discussion is that the authors think that ‘thermogenic’ carbon is necessary to account for the PETM–in line with the somewhat well-known idea of volcanic combustion of coal beds, as mentioned a couple of times in Mark Lynas’s “Six Degrees.”

[Response: Yes, that is their conclusion. ]

(That last’s on my mind, since I’m in the process of updating my summary review of that book here. So far, I’ve done a couple of updates in the summary table articles on the 3- and 4-degree worlds, for anyone who may care.)

Any elaborations on any of this are welcome, but not necessarily expected–I, like most of us, am grateful for the effort that goes into the site as it is. Thanks, all…

“We, Kimo Sabe?” I’m not daring to assert that; it’s above my pay grade! Just daring to ask (im?)pertinent questions… and appreciating the answers I do get regardless.

But I think the response does clarify one thing for me: the “The warming has to be due to CO2, as evidenced by its duration,” refers primarily not to the duration of the onset itself (which is what I was naively focussing on), but rather the fact that the warming lasted over millennial timescales.

I was taking seriously the description from Joe Romm’s site, which specifies 5 C in 13 years. (Head-spinningly fast, I think we’d all agree.) If warming was indeed that quick, then methane or other short-lived GHGs could have been involved, potentially invoking a spectrally broader and more intense radiative forcing. (The methane idea, I suppose, came also from the Lynas, as he mentioned that as one of the ‘usual suspect’ mechanisms proposed to account for PETM. I was actually surprised to note, upon rereading this sequence, to note that methane was not mentioned until I unwittingly smuggled the notion in myself. Though I note it’s been mentioned since.)

I do not think they say the _temperature_ transition took 13 years. I think they say that the isotope excursions and pH drop occurred quickly. They do not claim much about the timescale of the temperature response.

In a new paper in the Proceedings of the National Academy of Sciences, Morgan Schaller and James Wright contend that following a doubling in carbon dioxide levels, the surface of the ocean turned acidic over a period of weeks or months and global temperatures rose by 5 degrees centigrade – all in the space of about 13 years.

Thanx again Prof. Archer for your comment. I guess that while I accept the delta-018 is strong evidence for the annual nature of the clay couplets, but I question the absolute temperature scale, since, as they point out freshwater flux affects the isotope excursion.

“The variability in delta-O18 reflects changes in temperature, the delta-O18 of water … or a combination of both…We maintain that temperature must be a significant component of the intracouplet delta-18O variability, …”

So freshwater flux increased (or decreased) continually over the 13 year period, would result in drift of delta-O18 excursion. Now, they do point out that (in regard to the annual cycle)

“the required changes in salinity are far greater than are observed on the modern mid-Atlantic
shelf or even at sites at comparable water depths off the Amazon fan ”

But those were times of great turmoil indeed, so i still have a question mark in my mind on the absolute temperature scale. Especially in light of Prof. Zeebe comment that such a large temperature swing in such a short time would require decoupling ocean heat capacity from surface temperature, which would have required strong magic.

[Response: Strong indeed. But as Hank also notes, this isn’t a global average, maybe as you say changes in hydrology contributed. David]

Are they relying on only one site for the claim that “global” temperatures changed at this rate? How big a ‘catchment’ source for the sediment? Is the argument that ‘nothing but a global change could produce this result’?

[Response: What else would they be relying on? A site like this doesn’t come every day, there certainly aren’t a global array of them. This was just some coastal wash someplace, think Long Island Sound or some coastal setting where mud was accumulating relatively quickly. Assuming that the CaCO3 in it was produced in the water column, it’s pretty much local. I guess the argument is, nothing but local temperature change can explain the result. The leap to global has to appeal to an assumption about climate dynamics. David]

Gavin remarked here some years ago, after a China trip, that the meeting gave hope that sediment records would begin to be cross-correlated, rather than studied independently.

That’s the “what else” I was wondering about — what else besides this one site was (or could be) looked at to make the “global” statement, and whether there are any other imaginable explanations for the single site record besides a global atmospheric change.

And I was wondering where the source of the sediments was, if they know (is it for example a river outflow collecting sediment from a catchment? Or a deep ocean basin getting sediment from a vast area of ocean?)

Today, members of AMEG, the Arctic Emergency Methane Group, will be meeting in San Francisco with Professor Wadhams to discuss the growing threat of methane from the loss of the Arctic ice. The group will also be looking at possible geo-engineering ideas to avert climate change disaster.

I’d guess there’s no chance of requiring the geoengineers’ CO2 to be pumped back down into the formation while they’re sucking out all the methane, since their argument for sucking out the methane is that It’s All Gonna’ Blow so why not drill wells, sell and burn it…..

“…whether there are any other imaginable explanations for the single site record besides a global atmospheric change.”

atmosphere is well mixed on 13 yr scale including delta-C13

“And I was wondering where the source of the sediments was, if they know (is it for example a river outflow collecting sediment from a catchment? Or a deep ocean basin getting sediment from a vast area of ocean?)”

A seasonality trigger for carbon injectionat the Paleocene-Eocene thermalmaximum

The PETM is associated with rapid and massive injections of 13 C-depleted carbon into the ocean-atmosphere system reflectedas a prominent negative carbon isotope excursion (CIE) in sedimentary components. 5 Earth’s surface and deep ocean waters warmed by ∼ 5 ◦ C, of which part may have oc-curred prior to the CIE. However, few records document continental climatic trendsand changes in seasonality have not been documented. Here we present the firsthigh-resolution vegetation reconstructions for the PETM, based on bioclimatic anal-ysis of terrestrially-derived spore and pollen assemblages preserved in an expanded 10 section from the Central North Sea. Our data indicate reductions in boreal conifersand an increase in mesothermal to megathermal taxa, reflecting a shift towards wetter and warmer climate. We also record an increase in summer temperatures, greater inmagnitude than the rise in mean annual temperature changes. Within the CIE, vegetation varies significantly with initial increases in epiphytic and climbing ferns, and 15 development of extensive wetlands, followed by abundance of Carya spp. indicative ofbroadleaf forest colonization. Critically, the change in vegetation we report occurs prior to the CIE, and is concomitant with anomalous marine ecological change, as represented by the occurrence of Apectodinium augustum. This suggests that amplifications of seasonal extremes triggered carbon injection.

Critically, several records suggest that some of the warming preceded the injectionof 13 C-depleted carbon by several thousands of years, which may have triggered the injection of carbon (Sluijs et al., 2007; Secord et al., 2010). However, no data exist to 10 evaluate if this warming included a seasonal bias. Such small time lags can only be re-solved in stratigraphically expanded sediment sections, typically from marginal marine areas because deep-marine sections are condensed due to the massive dissolution of carbonates (Zachos et al., 2005). The Central North Sea basin yields vastly expandedPETM sections because of massive sediment supply from the hinterland (Sluijs et al., 15 2007). Numerous of such successions have been retrieved by oil exploration and production companies, but generally have not been made publically available. We studiedShell Exploration and Production well 22/11-N1 (57 ◦ 39.46 N, 1 ◦ 8.444 E, present water depth ∼ 83 m) in the Central North Sea (Fig. 1).

Despite the relatively large uncertainties in precipitation estimates, our seasonal precipitation record using WMMP and CMMP (Fig. 4cand d) does provide additional insights into the climate of PETM interval. In particular,our WMMP estimates (Fig. 4d) show a brief shift to wetter conditions pre-CIE, which 15 although uncertainties are large coincides with the first common appearance of the freshwater algae Pediastrum. Our estimates also show a second more significant shift to higher summer precipitation (∼ 140 cm yr −1 ) late in the CIE initiation and into the CIE body. This latter shift in WMMP corresponds with an abundance of the freshwater peridinioid dinocyst taxon Bosedinia (Prauss, 2012) indicating enhanced continental runoff 20 and salinity stratification in the central North Sea Basin at this time associated with the higher summer precipitation.

The change in vegetation we report occurs prior to the CIE. It is concomitant with the onset of the Apectodiniumacme prior to the CIE in well 22/11-N1, representing the earliest sign of anomalousPETM-related environmental change also at other North Sea sites (Sluijs et al., 2007). 5 Within the CIE, there is significant reorganization of the vegetation with initial increases in epiphytic and climbing ferns (Polypodiaceae and Schizeaceae), and development of extensive wetlands, followed by abundance of Carya spp., indicative of broad leaf forests. Our precipitation estimates although have large uncertainties provide the first direct evidence for seasonally wetter summers briefly prior to the CIE and more per- 10 sistently during the main CIE itself. These shifts to wetter summers correspond with periods on enhanced continental runoff as expressed by the abundance of freshwater indicators such as the algae Pediastrum and the dinocyst taxon Bosedinia and areconsistent with enhanced hydrological cycling prior to, and during the PETM interval.The marked increase in WMMT and WMMP puts a new perspective on environ- 15 mental precursors to the injection of carbon during the PETM.

Previous studies found anomalous biotic change and at least regional warming to lead the CIE by thousands of years (Thomas et al., 2002; Sluijs et al., 2007; Secord et al., 2011). This suggested that early warming could have caused destabilization of submarine methane hydratesto cause injection of 13 C-depleted carbon into the global exogenic carbon pool. Recent 20 experiments with a fully coupled atmosphere–ocean climate general circulation model(GCM) supported this scenario (Lunt et al., 2011). In this model, enhanced seasonal contrasts through milankovitch forcing (Lourens et al., 2005), combined with a gradually warming late-Paleocene to early Eocene, forced a non-linear response in ocean circulation to warm intermediate waters. This mechanism, which explains not only the 25 PETM but also the smaller early Eocene events, should have caused hydrate dissociation if these were present in the early Paleogene (Lunt et al., 2011). Our results show the occurrence of such seasonal extremes just prior to the onset of the CIE and may thus represent the smoking gun of a climatologically forced threshold in the carbon cycle that caused the PETM. Link

Enhanced chemistry-climate feedbacks in past greenhouse worlds

Climate Feedbacks by Elevated Trace Greenhouse Gas Concentrations. Elevated trace GHG concentrations contributed an estimated positive forcing of approximately 1.7–2.3 W m-2 (Table S5) in addition to that of CO2 and produced equilibrium climate system responses resulting in widespread significant warming, especially in the high latitudes (Figs. 3 and 4). This positive climate feedback is greater than expected from the additional forcing alone, due to amplification by reduced surface albedo through melting of continental snow and decreased sea-ice coverage, especially in the wintertime. Polar amplification of warming arises because the initial baseline simulations underrepresent the warmth of ancient greenhouse climates. Because this issue continues to affect all coupled ocean-atmosphere models (e.g., 22–24), the warming (Fig. 3) represents the expression of positive biotic feedback mechanisms missing from earlier simulations of these climates obtained with prescribed PI concentrations of trace GHGs.

Overall, ecosystem-driven changes in chemistry induced climate feedbacks that increased global mean annual land surface temperatures by 1.4 and 2.7 K for the 2× and 4 × CO2 Eocene simulations, respectively, and 2.2 K for the Cretaceous (Fig. 3 E and F). The relative contribution of each trace GHG to increased Eocene and Cretaceous land temperatures at 4 × CO2, assessed with multiple separate coupled-ocean atmosphere HadCM3L model simulations, revealed methane and associated increases in stratospheric water vapor dominate, with nitrous oxide and tropospheric ozone contributing approximately equally to the remainder. Link

The forgotten methane source

Scientists from the Max Planck Institute for Nuclear Physics have now discovered that plants themselves produce methane and emit it into the atmosphere, even in completely normal, oxygen-rich surroundings. The researchers made the surprising discovery during an investigation of which gases are emitted by dead and fresh leaves. Then, in the laboratory and in the wild, the scientists looked at the release of gases from living plants like maize and ryegrass (see image 1). In this investigation, it turned out that living plants let out some 10 to 1000 times more methane than dead plant material. The researchers then were able to show that the rate of methane production grew drastically when the plants were exposed to the sun.

In terms of total amount of production worldwide, the scientists’ first guesses are between 60 and 240 million tonnes of methane per year. That means that about 10 to 30 percent of present annual methane production comes from plants. The largest portion of that – about two-thirds – originates from tropical areas, because that is where the most biomass is located. The evidence of direct methane emissions from plants also explains the unexpectedly high methane concentrations over tropical forests, measured only recently via satellite by a research group from the University of Heidelberg.

Biogeochemistry and Budgets of Methane (IPCC AR4)

Geological sources of CH4 are not included in Table 7.6. However, several studies suggest that significant amounts of CH4, produced within the Earth’s crust (mainly by bacterial and thermogenic processes), are released into the atmosphere through faults and fractured rocks, mud volcanoes on land and the seafloor, submarine gas seepage, microseepage over dry lands and geothermal seeps (Etiope and Klusman, 2002; Etiope, 2004; Kvenvolden and Rogers, 2005). Emissions from these sources are estimated to be as large as 40 to 60 Tg(CH4) yr–1. Link

The chief biological impact of the PETM was the mass extinction of deep-sea benthic forams. Approximately 35-50% of all species of this group went extinct during the event. Interestingly, the benthic forams were almost unaffected by the environmental impacts at the Cretaceous-Tertiary (K-T) boundary, a time when the dinosaurs and many other groups went extinct. This paradox reflects the fact that the PETM had far more severe impact on deep-water environments, whereas the K-T boundary has more impact on the surface ocean and land. Although extinction was focused in the deep sea, the PETM actually did result in abrupt changes to life in the surface ocean, one of the most dramatic of which was the occurrence of blooms of dinoflagellates in the coastal oceans.

These dinoflagellate blooms, which can be thought of as ancient red tides, are a sign of major environmental stress in the coastal zone possibly as a result of the increased runoff of water from the land. Elsewhere in the oceans, the environmental changes during the PETM led to shifts in the distribution of plankton groups, with tropical species invading the high latitudes and high-latitude species dwindling in abundance. However, at the end of the event, the distributions and abundance of different taxa reverted to close to where they were before the PETM. Link

Sidd, can you tell me more about the conditions at the time where that sediment was laid down, and whether for example it’d make any difference if the sediments were material brought in from the ocean during seasonal storms year after year, versus washed down the river from inland during the same annual storm cycle? Could there be something different about the local source material — ocean plankton producing one kind of sediment exposed to the atmosphere, versus say peat bogs or coal seams being washed out upstream and delivering locally derived material directly to the sediment beds? I’m seriously trying to get more of a picture than I have been able to come up with, wondering what possibilities can be imagined (and then how they can be eliminated).

Understood these kinds of sediments are very rare and finding more around the world hasn’t happened yet — and when it does, and the records get correlated, we’ll have a clear picture of a global change happening. Til we do — what else if anything -could- be imagined to produce such a local record.

The notions out there in the literature include for example a comet impact, or spontaneous combustion of coal beds, causing a carbon spike. Could anything local and small scale produce a local effect in the sediments, or does it have to be global “because …”.

… it was a different world the last time, around 56 million years ago. The Atlantic Ocean had not fully opened, and animals, including perhaps our primate ancestors, could walk from Asia through Europe and across Greenland to North America. They wouldn’t have encountered a speck of ice; even before the events we’re talking about, Earth was already much warmer than it is today. But as the Paleocene epoch gave way to the Eocene, it was about to get much warmer still—rapidly, radically warmer.

The cause was a massive and geologically sudden release of carbon. …

… In the eastern Pyrenees, Birger Schmitz has found more dramatic evidence of catastrophic flooding during the PETM. He and colleague Victoriano Pujalte, from the University of the Basque Country in Bilbao, Spain, identified the trademark carbon spike at the base of a rock formation that, though now high in the mountains, probably lay on a coastal plain back then. A field of boulders had been washed out of the budding mountains and tossed onto a vast floodplain that the scientists believe extended over thousands of square miles. Some boulders were two feet across and could have been put there only by exceptionally violent water. Deposited over centuries by channel-jumping rivers, they’re like fossil imprints of the energy in the hothouse atmosphere.

While bean trees were blooming in the Bighorn Basin, Apectodinium was blooming all over the ocean. The species is an extinct form of dinoflagellate—a group of single-celled plankton, some of which today give rise to toxic blooms known as red tides. All dinoflagellates have two flagella that they whip around to propel themselves through the water, a distinctive maneuver that Henk Brinkhuis, of Utrecht University in the Netherlands, demonstrated for me one day by folding one arm through his legs, the other around his slightly protruding belly, and flapping both. In the winter Apectodinium cells would retreat into hard cysts that sank to the seafloor. The following spring a flap on each cyst would fly open like a trapdoor—Brinkhuis stuck a finger in his cheek and made a cork-popping sound. The cell would then crawl out and ascend to the sea surface, leaving the empty cyst behind for Brinkhuis and his colleague Appy Sluijs to recognize in sediment samples 56 million years later—its open flap the only clue to a space-alien-like life history. In Brinkhuis’s office there is a poster that reads, “Everything I know I learned from Star Trek.”

Before the PETM, Brinkhuis and Sluijs find Apectodinium only in the subtropics. But in PETM sediments they find it all over the world—confirmation that the ocean was heating up everywhere. In the Paleocene the summer water temperature in the Arctic Ocean was already around 64 degrees Fahrenheit; during the PETM it shot up to around 74. Swimming there would have been like swimming today on the mid-Atlantic seaboard, which, judging from a New Jersey sediment core that Brinkhuis and Sluijs have also analyzed, would have been like the Caribbean. Today the water at the deep seafloor is just above freezing; in the PETM it was in the 60s.

So even before it began sea level was much higher, the icecaps had already melted — then something else happened ….

At minute 14, it is pointed out that sea-bottom-dwelling creatures are moving further and further into the Arctic. Has anyone included the effect of these new creatures in projecting what the stability of seabed permafrost and hydrates may be going forward?

Hank Roberts: So even before it began sea level was much higher, the icecaps had already melted — then something else happened ….

The positive biotic feedback mechanisms on land and in the Ocean, which lead to non-linear responses which changed ocean circulation to warm intermediate waters and thus could have created the conditions for large spikes of carbon isotope excursions.

new GSL statement outlines evidence that a relatively modest rise in atmospheric CO2 levels and temperature leads to significant sea level rise, with oceans more acidic and less oxygenated.

The Geological Society of London (GSL) says the sensitivity of the Earth’s climate to CO2 could be double earlier estimates.

The Society has published an addition to a report by a GSL working party in 2010, which was entitled Climate change: Evidence from the Geological Record.
The addition says many climate models typically look at short term, rapid factors when calculating the Earth’s climate sensitivity, which is defined as the average global temperature increase brought about by a doubling of CO2 in the atmosphere.

Scientists agree that a doubling of atmospheric CO2 levels could result in temperature increases of between 1.5 and 4.5°C, caused by rapid changes such as snow and ice melt, and the behaviour of clouds and water vapour.

But what the GSL now says is that geological evidence from palaeoclimatology (studies of past climate change) suggests that if longer-term factors are taken into account, such as the decay of large ice sheets, the Earth’s sensitivity to a doubling of CO2 could itself be double that predicted by most climate models. Link

Gavin, they’ve quit mentioning “metastable hydrate” in the public releases.

Seems the worry is a blowout of gas due to holes and cracks in the permafrost — but would they ask the petroleum folks to do anything different than they’re already doing? Drill more and faster for gas?

What about just encouraging some of the beasties that already thrive in high methane and low oxygen to propagate on the seabed? There’s stuff that could thrive in those conditions if the temperature’s close enough: